From Teflpedia

Behaviourism (/bəˈheɪvɪərɪzm/) is a school of thought that behaviour comes from stimulus-response. Think Pavlov's dogs salivating to bells.

In its weak form, it states that students need praise and happiness to learn, and is little different from the affective filter hypothesis.

In its strong form, as a methodology (behaviourist pedagogy), it strong avoidance of errors doesn't fit with modern learning theories, and its emphasis on controlled drilling and lack of creativity might ironically raise students' affective filters so they won't learn.